EP 0636267 A1 19950201 - EXTENDED FREQUENCY RANGE HELMHOLTZ RESONATORS.
Title (en)
EXTENDED FREQUENCY RANGE HELMHOLTZ RESONATORS.
Title (de)
HELMHOLTZRESONATOREN MIT ERWEITERTEM FREQUENZBEREICH.
Title (fr)
RESONATEURS HELMHOLTZ A GAMMES DE FREQUENCES ETENDUES.
Publication
Application
Priority
- US 9203042 W 19920414
- US 16788688 A 19880314
Abstract (en)
[origin: US5119427A] Extended frequency range Helmholtz resonators particularly useful for sound absorption over a relatively wide frequency range are disclosed. The resonators are conventional Helmholtz resonators with the addition of an active acoustic driver in the resonator cavity driven at appropriate amplitudes, frequencies and phases to provide a high degree of absorption of sound not only at the resonant frequency of the resonator, but for substantial frequency bands above and below the resonant frequency. To provide the active drive to the acoustic driver in the resonant cavity, one or more microphones are used to detect the sound to be absorbed, which signal is processed and amplified to provide a drive to the acoustic driver to best absorb the incoming sound. Various embodiments are disclosed.
IPC 1-7
IPC 8 full level
G10K 11/178 (2006.01); G10K 11/16 (2006.01); G10K 11/172 (2006.01)
CPC (source: EP US)
G10K 11/172 (2013.01 - EP US); G10K 2210/109 (2013.01 - EP US); G10K 2210/121 (2013.01 - EP US); G10K 2210/32271 (2013.01 - EP US); G10K 2210/32272 (2013.01 - EP US); G10K 2210/512 (2013.01 - EP US)
Designated contracting state (EPC)
DE ES FR GB IT
DOCDB simple family (publication)
US 5119427 A 19920602; AU 2257192 A 19931118; DE 69231189 D1 20000727; EP 0636267 A1 19950201; EP 0636267 A4 19960515; EP 0636267 B1 20000621; JP H07508357 A 19950914; WO 9321625 A1 19931028
DOCDB simple family (application)
US 16788688 A 19880314; AU 2257192 A 19920414; DE 69231189 T 19920414; EP 92914363 A 19920414; JP 51826093 A 19920414; US 9203042 W 19920414